通过对电感耦合等离子体质谱(ICP-MS)的工作条件和参数进行优化,建立了ICP-MS测定铅同位素比值的精确方法,测量了2007—2009年南极中山站采集到的气溶胶样品中208Pb/206Pb、207Pb/206Pb和206Pb/207Pb的比值。结果表明,南极大气气溶胶中铅同位素比值在逐年缓慢地发生线性变化,线性相关系数为0.996 2;气溶胶铅同位素示踪揭示南极附近国家(除南非)释放的铅可能成为南极大气中铅的重要来源。
By optimizing the operating parameters,a methodology for a precise and accurate determination of lead isotope ratios based on inductively coupled plasma mass spectrometry(ICP-MS) has been developed.The developed method has been applied to determine the lead isotope ratios(208Pb/206Pb,207Pb/206Pb and 206Pb/207Pb) in aerosol samples collected at the Antarctic Zhongshan Station during 2007—2009.The result indicated that lead isotope ratios of the Antarctica aerosol samples(208Pb/206Pb Vs 207Pb/206Pb) increased linearly year by year from 2007 to 2009 with a linear correlation coefficient of 0.996 2.Moreover,the lead isotopic composition of the aerosol in Antarctica collected at the Zhongshan Station was close to the values of the countries surrounding Antarctica(except South Africa),suggesting that the important source of lead in Antarctica atmosphere mignt be the lead released in these countries.